Door latch mechanism



N v- 21, 1 51 D. 0. SMITH 2,576,648

DOOR LATCH MECHANISM Filed Aug. 2'7, 1948 Fxca- GD /8 I9 20 V y m 37 Q 33 FIG. 3-

4/ 40 Y I Y I n INVENTOR.

AT TORNCY Patented Nov. 27, 1951 DOOR LATCH MECHANISM David C. Smith, Toledo, Ohio, assignor of forty per cent to E. W. Sauers, forty per cent to A. E. Giesey, both of Cleveland, and twenty per cent to Leroy I. Oblinger, Toledo, Ohio Application August 27, 1948, Serial No. 46,467

1 This invention relates to door latching mechanisms but more particularly to a house door latch of the type in which one of the bolt retracting elements can be rendered inoperative so that it can turn freely without retracting the bolt.

An object is to produce a new and improved door latching mechanism which is simple in construction, easy to assemble and efiicient in operation.

Another object is to provide a door latching mechanism with means for positively preventing retraction of the latch bolt by prying the latch bolt in a retracting direction by a screwdriver or some similar sharp instrument when the door is in latched position.

A further object is to improve the construction and operation of door latch mechanism of the type having rotary retracting members such as knobs and in which the outside knob may be caused to spin freely thus to prevent its use for latch bolt retraction.

Other objects and advantages of the invention will hereinafter appear, and for purposes of illustration but not of limitation, embodiments of the invention are shown on the accompanying drawings, in which Figure 1 is a transverse sectional view of a door latching mechanism showing the latch in latched position;

Figure 2 is an enlarged fragmentary sectional view showing the latch bolt blocking member retracted sufficiently so that upon further movement of the retracting element, the latch bolt will then be retracted or withdrawn from keeper engaging position;

Figure 3 is a sectional view substantially on the line 4-4 of Figure 1, showing the bolt retracting members; and

Figure 4 is a fragmentary elevation of the door edge showing the latch bolt nose and the lockin slide for the latch bolt.

The illustrated embodiment of the invention comprises a door l suitably mounted on hinges (not shown) for opening and closing movement relatively to a door frame H having a suitable jamb l2. Fitting in a hole I3 bored from the free edge of the door is a metallic cylindrical housing M, the front end of which is opened and the rear end of which is closed by an integral wall l5 which has an aperture 16 therein. Slidable within the housing I4 is a. latch bolt I! which has a latching nose [8 with an inclined keeper engaging surface, one side of which is flat as indicated at [8. An apertured flat plate [4a is suitably secured to the face of the door, abuts against the 1 Claim. (Cl. 292- 169) outer end of the housing l4, and provides a stop for limiting the outward movement of the bolt, the latter being shouldered adjacent the bolt nose l8. v

Slidable along the flat surface l9 relatively to the bolt nose 3 is an arcuate slide 20 which has an extension 2| terminating in a tube 22. In the rear end portion of the bolt I1 is a socket 23, the open end of which is covered by a plate 24 suitably secured to the rear end of the bolt. A cylindrical cam 25, the rear edge portion of which is beveled, is movable within the socket 23. The cam 25 has a cylindrical extension 26 into which is fitted a rod 21 and abutting against the shoulder formed by the extension 26 is a disc 28. A helical coil spring 28 bears at one end against the disc 28 and at the opposite end against the housing wall l5. It will be manifest that the spring 29 tensions the latch bolt I! and normally urges it to its latching position in which the nose I 8 passes through the apertured keeper plate 30 and into a socket 3| in the door jamb l I.

The tubular extension 22 of the latch bolt looking slide 20 is guided by a pin 32 which is riveted at 33 to the casing wall I5 and surrounding the pin 32 is a helical coil spring 34 which bears at one end against the casing wall [5 and at the other end against a rear end of the tubular extension 22. Fixed at one end to the outer end portion of the pin 32 is a leaf spring 35 which is bent to provide a shoulder 36 and terminates in a substantially straight end portion 31. When the latch bolt I1 is in its advanced or latching position as shown in Figure l, the shoulder 36 is disposed directly in rear of and in blocking relation to a wall 38 of the socket 23, the wall 38 having a rounded or curved surface as clearly shown on Figure 2. When the spring is in blocking position, it will be apparent that the latch bolt I! can not be retracted by forcing a pointed instrument between the edge of the door and the frame to cam it rearwardly. In this manner, the latch bolt is positively blocked against retracting movement. However, upon movement of the rod 21 to the right of Figures 1 and 2, the cam 25 forces the shouldered portion 36 outwardly with respect to the wall 38 to such position that the rounded or curved surface of the wall 38 will further depress the spring 35 so that upon further movement of the rod 21, the latch bolt may be readily retracted and at the same time, the engagement of the end of the cam 25 and the adjacent edge of the tubular extension 22 causes the slide 20 to move to the right of the figure in a retracted direction.

As soon as the rod 21 is released, the springs 29 and 34 cause the bolt and the bolt blocking slide 20 to advance to operative or latching position. At that time, the spring 35 snaps out of engagement with the side wall of the bolt I! so that the-,Sh u1der3B isin abutting engagement with the wall portion 138, therebyrpositivelyholding the bolt in its latching position and militates against its retraction except by movement of the rod 21.

When the door is open, both the bo'lt l'l and slide 20 are in advanced position, the camjiheing in its rearward position-relative,tothe socket 23 holding the blocking spring -35 awayjrom bolt blocking position. Therefore, in slamming the blocking spring 35 then "being slightly cammed inwardly by the rounded surface ;on :the wall portion 38. Thus the slide functions to enable ,thebolt to retract .in slamming ,the .deor. When the door is in latched position, the ,slide .isheldretracted and unde r ..tension by its, engagement with the striker or keeper plate.

Atits in e nd. a substantially ru -shap d actuator ;3 9jiS'- 1'iVe,t. d position, ,the actuator having wings AB ,extending at substantially right angles ,tofleach arm of the U-shaped actuator. Engageable with the wings All are fingers M which areintegral ,witha sleeve ,42. Suitably fixed to {the sleeve '42 is an elongate sleeve M 30 which;is;rotatably mounted-in an escutcheon 45 and suitably -secured as by a set screw (not shown) rto itheputerendportion of the sleeve 44 is aknob 4 6. Manifestlyyby turning the knob ;in oneldirection-orthe other, one'of the fingers AI will, upon engagement with its respective ing-:40, :rollbackorretract the latch bolt mech- :anism ;as .above described.

It is'to be understood thatnumerous changes -details 7 of construction, arrangement and operation may be effected without departing from the spirit of the invention especially as defined in the appended claim.

What I claim is:

A door latch comprising a latch bolt assembly joramollnting Lin. a socket iii-the door, comprisgin-g a cupa-shaped casing vopen at theforward end,

a spring-tensioned latch bolt slidable in said casring and having a latching nose projectable from 10 said casing, a retracting rod, the closed end of said casingbeing apertured to accommodate said ,md, a-cam element'on the inner end of said ,-rod,-:said,;bolt,being socketed at the inner end -.-.t0:1-'.eeeive-;said :eam: element and to afford limited I vmovementatherein,'means closing the end of said the door, both the bolt and slide retract to ether,

socket, a shoulder on said bolt adjacent said socket, a'leaf spring element carried by said casing zamd jhaving a shouldered portion engaging said shoulder on said bolt thereby positively to block retracticn '.of ,said ,bolt said scam element 2a ,nertloneof said bolt and movable relatively ,theretmeatubular extension onisaid. slide enclosing said spring element and iengageable by c said cam for retracting the same, and spring means 'for :tensioning saidrtubular extension.

, DAVDJ.C.;SMITH. l

REFERENCES CITED {theifbllowlng:referenoes are cof record in the file of this patent: 7

UNITED STATES PATENTS Number Name Date 1,148,559 1SparkS A 1 15 12,250,727- ,Schlage V. .July 129, A941 Hillgren {July 19, 19.45 

